Substrate treatment device

ABSTRACT

A device for the treatment of substrates has a container having walls and being filled with a treatment fluid. At least one substrate carrier is mounted in the container so as to move the substrates vertically in a reciprocating manner without a substrate support. Substrate side walls are provided between the substrates and the container walls. These substrate side walls extend parallel to the substrates and are vertically movable in a reciprocating manner with the substrates.

BACKGROUND OF THE INVENTION

The invention concerns a device for the treatment of substratescomprising a container filled with a treatment fluid, having at leastone substrate carrier that moves the substrates vertically in areciprocating manner without a substrate support.

Devices of the aforementioned kind have been known, for instance, fromDE 44 13 077 A1 and DE 195 46 990 A1 of the applicant of this presentpatent application and are described in the German patent applicationsDE 195 37 879.2, DE 196 16 402.8, DE 196 52 526.8 or DE 196 37 875.3 ofthe same applicant as well, which have not been published as of thefiling date of this application. Devices of the aforementioned kind arebeing used especially advantageously for the treatment of wafers. To drythe substrates, the substrate carrier is lifted, so that the substrateson the substrate carrier are lifted out of the treatment fluid, forexample, a rinsing agent, and may be dried utilizing the Marangonimethod. In these devices the substrates are moved in the fluid containerindependent of substrate support, for example, independent of substrateand wafer cassettes, which are known, e.g., from DE 42 23 327 A1 or DE34 29 232 A1. When rinsing or drying such substrates, these substratesupports have the disadvantage, among others, that an optimal uniformfluid flow in the fluid container is not possible because the cassettepresents a flow obstacle and because the substrates in such a cassettecannot be treated with ultrasound, as suggested, for example, in the asyet unpublished documents DE 197 22 473 A1 or DE 196 16 402. Thesubstrate support or cassette also presents a disadvantage during dryingof the substrates for example, wafers, because due to their largesurfaces area, edges, corners, and slots they can be dried only withdifficulty and with a great time expenditure.

In the conventional devices in which the substrates are reciprocatedvertically by a substrate carrier independent of a substrate support orcassette, at least at the outer surfaces of the corresponding substratesand the parallel extending container walls, a relative motion occurs,subjecting the outer surface of the substrates due to this relativemotion to electrical charging effects that adversely affect thisprocess, especially, if the substrates are highly sensitive wafers forchip manufacturing. Due to the relative motion between the externallypositioned substrates of a substrate package and/or the differentmaterials of the substrates, on the one hand, and the container walls,on the other hand, flow conditions at the side areas of the substratepackage differ from the flow conditions between the substrates withinthe substrate package. Therefore, externally positioned substrates, orat least the side areas of externally positioned substrates facing thecontainer wall, are treated, rinsed or dried less efficiently, so thatdisadvantages are observed and the productivity of the entire device isunsatisfactory.

Based on this, the object of the invention is the development of adevice that can achieve a homogeneous treatment process, for instance,rinsing and drying, for all substrates regardless of their arrangementwithin the container.

SUMMARY OF THE INVENTION

The object of the invention is inventively solved by providing substrateside walls between the substrates and the container walls that extendparallel to the substrates and are vertically movable in a reciprocatingmanner with the substrates. By the inventive use of substrate side wallsthat separate each substrate package, the flow conditions at the outersurfaces of the outermost positioned substrates are no different fromthe conditions between substrates within the substrate package, thusproviding the same efficient treatment, rinsing and drying results.These externally positioned substrates must therefore not be rejected asflawed products. Furthermore, no electrical charges are caused by thesubstrate side walls at the externally positioned substrates becausethere is no relative motion between the outwardly positioned substratesand the container wall.

Advantageously, the substrate side walls are mechanically connected withthe substrate carrier and are vertically movable in a reciprocatingmanner with it. The arrangement is thus constructively simple.

It is especially advantageous to position a substrate carrier armoutside the substrate area formed by the substrate side walls, whereinthe substrate carrier arm is positioned advantageously in an arm slotwithin one of the container walls. In this manner, the inner volume ofthe container can be minimized, which is especially advantageous inregard to time savings for filling and draining and, in particular, inregard to the required treatment fluid volume. The savings of treatmentfluid, for example, rinsing fluid, are important in particular, inregard to the costly materials required, recycling procedures, andpossible environmental harm.

According to another very advantageous embodiment of this invention,inlet jets and/or openings for the introduction of the treatment fluidare provided within the arm slot. In this manner, proper circulation ofthe treatment fluid within the arm slot and a rinsing of the arm slot isensured, thus preventing the higher contamination levels of thetreatment fluid within the arm slot as well as between the substratecarrier arm and the arm slot.

The inventive device is advantageously used for the drying processutilizing the Marangoni method. As described in detail in the documentsand applications of the applicant mentioned above, a gas, advantageouslyisopropyl alcohol, nitrogen or a gas mixture of these components, isdirected, for example, utilizing a hood positioned above the container,onto the fluid surface to improve and shorten the drying processutilizing the Marangoni effect. According to an advantageous embodimentof this invention, a tube within the arm slot and/or substrate carrierarm is provided for the controlled discharge of the gas above thetreatment fluid when the gas within the hood is displaced by the liftingof the substrates and substrate side walls.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in the following with the aid of a preferredembodiment. It is shown in:

FIG. 1: a schematic top view of the inventive device, and

FIG. 2: the device of FIG. 1 in cross section along the section lineII—II.

DESCRIPTION OF PREFERRED EMBODIMENT

A fluid container 1 is comprised of longitudinal walls 2, 3 andtransverse walls 4, 5. Extending parallel to the perpendicular walls 4,5 and adjacent to them, substrate side walls 6, 7 are provided in thefluid container 1 that are connected to a substrate carrier 8 andvertically movable in a reciprocating manner with this carrier in thefluid container 1. The substrates 9 are positioned between the substrateside walls 6, 7, extending parallel to them and being supported by thesubstrate carrier 8. In the shown embodiment, the substrate carrier 8 isknife-shaped and the substrates are guided in non-represented guidingslots in or at the longitudinal walls 2, 3 of the fluid container 1.

The substrate carrier 8 is attached to a substrate carrier arm 10positioned within an arm slot 11. The substrate carrier arm slot 11 issupplied with treatment fluid from the bottom in the same manner as theinside of the fluid container 1. The fluid rises to the top and isdischarged across the overflow edge or an opening, as described in theabove mentioned publications and applications of the applicant.

During the lifting of the substrates from the fluid container 1, thesubstrate side walls 6, 7 that serve as separation plates for thesubstrates 9 in regard to the transverse walls 4, 5 of the fluidcontainer 1, are lifted with the substrates, thus providing homogeneous,steady flow conditions within the substrate package as well as along theexternally positioned substrates 9 of the package and at the outwardlyoriented surfaces of these substrates. In this manner, in contrast toconventional devices, it is possible to treat, rinse and/or dryexternally positioned substrates 9 in the same manner as othersubstrates 9, so that these substrates 9 must not be rejected. This alsoprevents a high amount of rejects caused by charging effects at least ofthe externally positioned substrates 9 resulting from the relativemotion of these substrates 9 in respect to the horizontal walls 4, 5 ofthe fluid container 1. The substrate side walls 6, 7 are advantageouslycomprised of a wall surface at least the size of the substrate surface,thus shielding and separating the entire substrate area from thehorizontal walls 4, 5 of the fluid container 1.

The embodiment of the arm slot 11 in one of the two horizontal walls 4,5 of the fluid container 1 allows to minimize the container volume,optimizing not only the flow conditions, but also saving costlytreatment fluid that is expensive to recycle and possiblyenvironmentally harmful.

The gas directed onto the surface of the treatment fluid can bedischarged in a controlled manner through the arm slot 11 and/orsubstrate carrier arm 10, when the gas is displaced by the liftingsubstrates and substrate side walls within a hood positioned above. Theinvention has been disclosed with the aid of a preferred embodiment.However, persons skilled in the art may be able to implement variousalterations, designs and modifications without departing from the gistof the invention. For example, it is possible to use substrate carriers8 that support the substrate without using guiding slots in the fluidcontainer 1. It is also possible to provide an arm slot 11 in bothhorizontal walls 4, 5 if this should become a necessary requirement dueto the number or the weight of the substrates. Furthermore, the jets,openings, diffusers and other inlet devices for introducing thetreatment fluid, for example, a rinsing agent, from the bottom of thefluid container 1 and/or from the arm slot 11 may be selected accordingto the respective requirements. To avoid repetition concerning thisembodiment, the German applications DE.196 44 253.2, DE 196 44 254.0 andDE 196 44 255.9 of the same application date are incorporated byreference into the present patent application.

The specification incorporates by reference the entire disclosure ofInternational Application PCT/EP97/05406 of Oct. 1, 1997.

The present invention is, of course, in no way restricted to thespecific disclosure of the specification and drawings, but alsoencompasses any modifications within the scope of the appended claims.

What is claimed is:
 1. A device for the treatment of substratescomprising: a container having walls and being filled with a treatmentfluid; at least one substrate carrier mounted in said container so as tovertically move substrates in a reciprocating manner without a substratecassette; substrate side walls provided between said substrates and saidwalls of said container, wherein said substrate side walls extendparallel to said substrate and vertically reciprocate with saidsubstrates.
 2. A device for the treatment of substrates according toclaim 1, wherein said substrate side walls are connected to said atleast one substrate carrier and vertically reciprocate with said atleast one substrate carrier.
 3. A device for the treatment of substratesaccording to claim 1, further comprising a substrate carrier armpositioned outside a substrate area formed by said substrate side walls,wherein said at least one substrate carrier is connected to saidsubstrate carrier arm.
 4. A device for the treatment of substratesaccording to claim 3, wherein one of said walls of said container has anarm slot and wherein said substrate carrier arm is mounted in said armslot.
 5. A device for the treatment of substrates according to claim 4,wherein said arm slot has a bottom side provided with one or more inletsselected from the group consisting of jets, openings, and diffusors. 6.A device for the treatment of substrates according to claim 4,comprising a tube arranged in said arm slot for discharging a gaspresent above the treatment fluid.
 7. A device for the treatment ofsubstrates according to claim 6, wherein said gas is isopropyl alcohol,nitrogen or a mixture of isopropyl alcohol and nitrogen.
 8. A device forthe treatment of substrates according to claim 1, wherein said device isused in a drying device utilizing the Marangoni method.
 9. A device forthe treatment of substrates comprising: a container having walls andbeing filled with a treatment fluid; at least one substrate carriermounted in said container so as to vertically move substrates in areciprocating manner without a substrate cassette; substrate side wallsprovided between said substrates and said walls of said container,wherein said substrate side walls extend parallel to said substrate andvertically reciprocate with said substrates; a substrate carrier armpositioned outside a substrate area formed by said substrate side walls,wherein said at least one substrate carrier is connected to saidsubstrate carrier arm, wherein one of said walls of said container hasan arm slot and wherein said substrate carrier arm is mounted in saidarm slot, said arm slot having a bottom side provided with one or moreinlets selected from the group consisting of jets, openings, anddiffusors.
 10. A device for the treatment of substrates comprising: acontainer having walls and being filled with a treatment fluid; at leastone substrate carrier mounted in said container so as to vertically movesubstrates in a reciprocating manner without a substrate cassette;substrate side walls provided between said substrates and said walls ofsaid container, wherein said substrate side walls extend parallel tosaid substrate and vertically reciprocate with said substrates; asubstrate carrier arm positioned outside a substrate area formed by saidsubstrate side walls, wherein said at least one substrate carrier isconnected to said substrate carrier arm, wherein one of said walls ofsaid container has an arm slot and wherein said substrate carrier arm ismounted in said arm slot; and a tube arranged in said arm slot fordischarging a gas present above the treatment fluid.
 11. A device forthe treatment of substrates according to claim 10, wherein said gas isisopropyl alcohol, nitrogen or a mixture of isopropyl alcohol andnitrogen.